"Properties and values of this variant are conflicting" - but they are not

I have a design system that I published as a library. I’m consuming this library in another file for a slide show. Up until now, I never got an error when trying to access variants in the slide show file. But as of today, I am getting this message for a seemingly random assortment of instances:
 

“The properties and values of this variant are conflicting. Change the applied values on this variant to resolve this.”

I don’t get this error when interacting with variants inside the authoring file. 

I looked up this error message on the Figma forum, and it says it appears when Figma detects that two variants are identical, regardless of whatever they’re named. But in my case, the variants are absolutely not identical. They have many differences in names and values and they have never produced this error either on the authoring or the consuming side until now. 

I saw that Figma dropped the “Slot” property recently (love it). I’m wondering if this update could have led to this error?